CN213807592U - Casing section mills with righting instrument - Google Patents

Abstract

Translated fromChinese

本实用新型涉及一种套管段铣用扶正工具。包括壳体、上挡块、扶正翼、下挡块、弹簧、推板、活塞、心轴、喷嘴及下接头。壳体轴向设置阶梯状通孔，径向设置偏心通孔，壁内设置矩形沉槽和矩形孔；上挡块、扶正翼、下挡块依次设置于矩形沉槽内；活塞设置于壳体的活塞腔室内，与壳体内壁构成滑动配合；推板下端与活塞通过螺栓连接，上端通过剪钉与壳体连接；下接头的上端通过螺纹与壳体下端连接；心轴下端通过螺纹与下接头连接，上端穿过活塞内孔延伸至壳体的阶梯孔内；弹簧套于心轴之外。段铣双层套管时，该工具可随段铣器通过内层套管下入，液压驱动扶正翼伸出并支撑在外层套管内壁，保证段铣器平稳工作，扶正效果好。

The utility model relates to a righting tool for milling a casing section. Including shell, upper stopper, centralizing wing, lower stopper, spring, push plate, piston, mandrel, nozzle and lower joint. The casing is provided with a stepped through hole in the axial direction, an eccentric through hole in the radial direction, and a rectangular trough and a rectangular hole in the wall; the upper block, the centralizing wing and the lower block are sequentially arranged in the rectangular trough; the piston is arranged in the casing The lower end of the push plate is connected with the piston through bolts, and the upper end is connected with the casing through shear nails; the upper end of the lower joint is connected with the lower end of the casing through threads; the lower end of the spindle is connected with the lower end through threads The joint is connected, and the upper end extends through the inner hole of the piston into the stepped hole of the casing; the spring is sleeved outside the mandrel. When segment milling a double-layer casing, the tool can be run down through the inner casing with the segment milling machine, and the hydraulically driven righting wings are extended and supported on the inner wall of the outer casing to ensure the smooth operation of the segment milling machine and good righting effect.

Description

Casing section mills with righting instrument

Technical Field

The utility model relates to a righting instrument, especially sleeve pipe section mills with righting instrument.

Background

As the production time of offshore fields increases, more and more wells continue to go non-productive, and immediate well abandonment is required for these non-productive wells to permanently eliminate their potential threat to the environment. The marine oil and gas exploration and development in China starts late, but the south China sea, the east China sea and the Bohai Bay all enter a marine permanent well abandoning stage to different degrees. The basic requirements for marine permanent well abandonment include 4 aspects: (1) sealing and protecting all fresh water and near fresh water layers; (2) packing protects all future production zones with commercial exploitation value; (3) preventing fluid from leaking and flowing out of the well; (4) and (4) clearing all facilities above the seabed, and cutting off the pipes below the mud line. Therefore, cement plugs are needed to be designed to form cement cementation between rock-rock and cement-stratum so as to plug a production layer and prevent oil and gas leakage. In some cases, all sections of the two layers of sleeves corresponding to the designed cement plug drilling position need to be milled, and then the cement plug is drilled. Conventional casing section milling techniques require section milling of two casing strings from inside to outside layer by layer. For example, when a 9-5/8 'X13-3/8' double-layer casing is milled in a section mode, the section milling device extends out of the 9-5/8 'casing to the target depth, and a short blade is extended out to firstly mill off a certain length of the 9-5/8' casing; and then the well is drilled until the section milling device with the long blade is replaced, and then the section milling device is lowered to a preset depth from the inside of the 9-5/8 'casing, and the 13-3/8' casing with a certain length is milled by extending the long blade section. In the section milling operation process, in order to reduce vibration of the underground tool and enable the section milling operation to be stably carried out, a centralizer needs to be installed below the section milling device, and the centering effect of the centralizer is better when the outer diameter of the centralizer is closer to the inner diameter of the casing. When the inner casing (9-5/8' casing) is milled in section, a conventional centralizer (fixed in outer diameter) is adopted. However, when the outer casing (13-3/8' casing) is milled in a section, the conventional centralizer cannot meet the requirements for not only enabling the centralizer to be inserted from the inner casing, but also achieving a good centralizing effect.

Chinese patent CN207944901U discloses a segment milling tool with a self-adjusting centralizer, which comprises an upper body, a cutting blade and an upper piston; the upper piston is provided with a spring cavity between the upper piston and the upper body, and an upper piston spring is arranged in the spring cavity and forms axial support for the upper piston; the lower part of the upper body extends to form a lower body, more than two centering block grooves distributed at intervals are formed in the cylinder wall of the lower body, and the centering blocks are connected in the centering block grooves through centering block positioning blocks and centering block pin shafts; the lower piston is arranged in the lower body, the upper part of the lower piston is in sliding sealing fit with the inner wall of the upper part of the lower body, the lower part of the lower piston is provided with a lug which is in axial sliding and radial supporting fit with the righting block, a spring cavity is arranged between the lower piston and the lower body, and the lower piston spring is arranged in the spring cavity and forms axial support for the lower piston. The utility model discloses a for reduce the external diameter size of section milling tool, designed one set of self-interacting external diameter in order to adapt to the centralizer of different wall thickness sleeve pipe internal diameters in section milling tool lower part, this self-interacting righting device is realized through the piece of righting of the formula of expanding outward that becomes an organic whole with section milling tool processing. The centralizing block is not provided with a cutting edge and does not have the capacity of cutting a casing, the centralizing block can be opened before the section milling block is opened and the casing is milled under the driving of the pressure difference of the drilling fluid, the radial vibration of the section milling tool during the working process is reduced by keeping the section milling tool centered in the section milling casing, and the stability and the efficiency of the section milling tool are improved. However, in the actual use process, the centralizing block adopts a fulcrum hinge mode, so that the contact area of the centralizing block and the casing is small, and the centralizing stability is poor.

SUMMERY OF THE UTILITY MODEL

The utility model discloses a solve double casing pipe section and mill the operation in-process, the outer sleeve pipe time-lag of section milling ware righting poor stability's problem provides a sleeve pipe section mills with righting instrument.

A centering tool for milling a casing section comprises a shell, an upper stop block, a centering wing, a lower stop block, a spring, a piston, a mandrel, a lower joint, a push plate and a nozzle; wherein:

the upper end and the lower end of the shell are provided with threads, the lower end of the shell is hermetically connected with the lower connector to form a hollow cylindrical structure, the lower section of the shell is provided with an expanded piston cavity, the upper section of the shell is circumferentially and eccentrically provided with a rectangular sink groove, and the middle section of the shell is provided with a rectangular hole axially corresponding to the rectangular sink groove of the upper section;

the mandrel is arranged in an expanding piston cavity at the lower section of the shell, the upper end of the mandrel is hermetically connected with the middle section of the shell, the lower end of the mandrel is hermetically connected with the lower connector through a reducing nozzle, a stepped through hole structure is axially arranged in the mandrel, a lower boss is arranged on the periphery of the mandrel, the lower part of the lower boss is in blocking fit with the lower connector, and a plurality of hydraulic through holes are radially distributed;

the piston is sleeved above the lower boss of the mandrel, the inner wall of the piston is in axial sliding sealing fit with the mandrel, the outer wall of the piston is in axial sliding sealing fit with the piston cavity of the shell, and the upper part of the piston is circumferentially provided with connecting surfaces which are in one-to-one correspondence with the rectangular holes;

the spring is sleeved on the mandrel above the piston;

the upper stop block, the righting wing and the lower stop block are sequentially arranged in the rectangular sinking groove, and the righting wing, the upper stop block and the lower stop block form sliding limit fit according to the same inclination angle;

and after the push plate penetrates through the rectangular hole in the middle section of the shell in a sliding manner, the outer inclined plane of the upper end of the push plate is in sliding limit fit with the inner inclined plane of the righting wing, and the lower end of the push plate is fixed with the piston connecting surface.

The above technical solution further comprises:

the upper end of the shell is radially provided with an eccentric through hole, the upper stop block is provided with a horizontal round hole d, a round hole e, a vertical flow channel a and a horizontal flow channel B, the eccentric through hole is crossed with the round hole e of the upper stop block, a throttling nozzle A is arranged in the round hole d, a throttling nozzle B is arranged in the eccentric through hole, one end of the throttling nozzle B is connected with the shell, the other end of the throttling nozzle B penetrates through the round hole e of the upper stop block and is communicated with a flow guide hole radially arranged on the shell, the throttling nozzle B is communicated with the throttling nozzle A through the flow channel B, and the throttling nozzle A is communicated with the rectangular sinking groove through the flow channel a.

The upper end of the push plate is connected with the joint part of the shell through shear pins; the radial eccentric through holes of the shell are uniformly provided with 3 along the circumferential direction of the shell, the whole sunk groove deviates from the axis of the shell and is uniformly provided with 3 along the circumferential direction of the shell, and the rectangular hole is communicated with the rectangular sunk groove and the stepped through hole along the axial direction and is uniformly provided with 3 along the circumferential direction of the shell.

The lower end of the upper block is provided with a T-shaped groove, an included angle between the T-shaped groove and the horizontal direction is 30-45 degrees, the axes of the round holes d and e are mutually vertical, and the axes of the flow passages a and b are mutually vertical; the upper end of the lower block is provided with a T-shaped groove, the included angle between the T-shaped groove and the horizontal direction is 30-45 degrees, and the middle part is provided with a rectangular through hole.

The upper portion of the piston is circumferentially provided with three connecting surfaces with an included angle of 60 degrees, and each external connecting surface is provided with a plurality of threaded holes.

The included angle between the inclined plane of the upper end of the push plate and the horizontal direction is 30-45 degrees, 2-3 blind holes are arranged on the side face, and a plurality of counter bores are arranged at the lower end.

The lower boss of the mandrel is in a regular hexagonal shape, and a plurality of hydraulic through holes along the radial direction are arranged on the hexagonal surface.

The joint part of the throttling nozzle B, the upper stop block and the shell is respectively provided with a sealing ring; the shear pin is connected with the joint part of the push plate and the shell.

The lower stop block is connected with the shell through a positioning block.

The upper end of the lower joint is provided with threads, the center of the lower joint is provided with a step-shaped through hole along the axial direction, and the upper end of the lower joint is connected with the lower end of the shell through the threads; the lower end of the mandrel is connected with the lower joint through threads, and the upper end of the mandrel penetrates through the inner hole of the piston and extends into the stepped hole of the shell.

The utility model has the advantages that: when an outer casing in the double-layer casing is milled in a section mode, the tool can enter the section milling device through the inner casing, and the centering wings are driven by hydraulic pressure to extend out and support the inner wall of the outer casing, so that the section milling device is guaranteed to work stably; after the operation of the section milling outer casing is finished, the righting wing can be retracted into the tool shell, and the well head is drilled through the inner casing.

Drawings

Fig. 1 is a schematic structural view of a casing section milling centering tool according to the present invention;

FIG. 2 is an enlarged partial view at P of FIG. 1;

FIG. 3 is a cross-sectional view taken at A-A of FIG. 1;

FIG. 4 is a cross-sectional view taken at B-B of FIG. 1;

FIG. 5 is a cross-sectional view taken at C-C of FIG. 1;

FIG. 6 is a cross-sectional view taken at D-D of FIG. 1;

FIG. 7 is a cross-sectional view taken at E-E of FIG. 1;

FIG. 8 is a cross-sectional view at F-F of FIG. 1;

FIG. 9 is a cross-sectional view taken at G-G of FIG. 1;

FIG. 10 is a cross-sectional view taken at H-H in FIG. 1;

FIG. 11 is a front view of the upper block (4) of FIG. 1;

FIG. 12 is a right side view of the upper stop (4) of FIG. 1;

FIG. 13 is a cross-sectional view at I-I of the upper stop (4) of FIG. 1;

fig. 14 is a schematic structural view of a casing section milling centering tool according to the present invention when a centering wing is extended;

FIG. 15 is a schematic view of a casing section mill centralizer according to the present invention in downhole operation;

in FIGS. 1-15, 1 is a housing, 2 is a lower stop, 3 is a righting wing, 4 is an upper stop, 5 is a throttling nozzle A, 6 is a throttling nozzle B, 7 is a piston, 8 is a push plate, 9 and 14 are screws, 10 is a lower joint, 11 is a mandrel, 12 is a nozzle, 13 is a positioning block, 16 is a spring, 17 is a shear pin, 27 is a piston pressurizing cavity, 101 is a radial eccentric through hole, 102 is a rectangular sink groove, 103 is a rectangular hole, 104 is a piston cavity, 401 is a circular section flow passage a and 402 is a circular section flow passage B, 403 is a circular hole d and 404 is a circular hole e, 801 is a blind hole, 802 is a counter bore, 19-26 is a sealing ring, 1101 is a hydraulic through hole, and 27 is a chamber B; 51. a drill stem; 52. an outer casing; 53. a cement sheath; 54. an inner casing; 55. a section milling device; 52. a centralizing tool for milling casing sections.

Detailed Description

The following will be described in further detail with reference to the accompanying drawings.

Example 1

Referring to fig. 1 and 3, a casing section milling centering tool comprises a shell 1, anupper stop block 4, acentering wing 3, a lower stop block 2, aspring 16, apiston 7, amandrel 11, alower joint 10, apush plate 8 and anozzle 12; wherein:

the upper end and the lower end of the shell 1 are provided with threads, the lower end of the shell is hermetically connected with the lower joint 10 to form a hollow cylindrical structure, the lower section of the shell 1 is provided with an expandedpiston cavity 104, the upper section of the shell is circumferentially and eccentrically provided with 3-5rectangular sinking grooves 102, and the middle section of the shell is provided with a rectangular hole 103 which axially corresponds to the upper section of therectangular sinking grooves 102;

themandrel 11 is arranged in an expanding piston cavity at the lower section of the shell 1, the upper end of the mandrel is connected with the middle section of the shell 1 in a sealing way, the lower end of the mandrel is connected with the lower connector in a sealing way through a reducingnozzle 12, a stepped through hole structure is axially arranged in the mandrel, a lower boss is arranged on the periphery of the mandrel, the lower part of the lower boss is in blocking fit with thelower connector 10, and a plurality of hydraulic throughholes 1101 are radially distributed;

thepiston 7 is sleeved above the lower boss of themandrel 11, the inner wall of the piston is in axial sliding sealing fit with themandrel 11, the outer wall of the piston is in axial sliding sealing fit with thepiston cavity 104 of the shell 1, and the upper part of thepiston 7 is circumferentially provided with connecting surfaces which are in one-to-one correspondence with the rectangular holes 103;

thespring 16 is sleeved on themandrel 11 above thepiston 7;

theupper stop block 4, the rightingwing 3 and the lower stop block 2 are sequentially arranged in therectangular sinking groove 102, and the rightingwing 3, theupper stop block 4 and the lower stop block 2 form sliding limit fit according to the same inclination angle;

and after thepush plate 8 penetrates through the rectangular hole 103 in the middle section of the shell 1 in a sliding manner, the outer inclined plane at the upper end of the push plate is in sliding limit fit with the inner inclined plane of the rightingwing 3, and the lower end of the push plate is fixed with the connecting surface of thepiston 7.

In the embodiment 1, the upper stop block is in direct sliding fit with the righting wing, and the liquid spraying assisting effect is avoided, but the structure is simple, and the practicability is high.

Embodiment 2, on the basis of embodiment 1, further includes:

referring to fig. 4 and 11, an eccentric throughhole 101 is radially arranged at the upper end of a housing 1, a horizontal round hole d403, a round hole e404, a vertical flow passage a401 and a horizontal flow passage B402 are arranged on anupper stopper 4, the eccentric throughhole 101 intersects with the round hole e404 of theupper stopper 4, a throttle nozzle a5 is arranged in the round hole d403, a throttle nozzle B6 is arranged in the eccentric throughhole 101, one end of the throttle nozzle B6 is connected with the housing 1, the other end of the throttle nozzle B6 penetrates through the round hole e404 of theupper stopper 4 to be communicated with a flow guiding hole radially arranged on the housing 1, the throttle nozzle B6 is communicated with the throttle nozzle a5 through the flow passage B402, and the throttle nozzle a5 is communicated with arectangular sink 102 through the flow passage a 401.

Referring to fig. 8, the lower end of thepush plate 8 is connected with thepiston 7 through abolt 9; referring to fig. 4, the radial eccentric throughholes 101 of the housing 1 are uniformly arranged in 3 numbers along the circumferential direction of the housing 1, the sunk grooves are wholly deviated from the axis of the housing 1 and are uniformly arranged in 3 numbers along the circumferential direction of the housing 1, and referring to fig. 5 to 7, the rectangular holes 103 are axially communicated with the rectangular sunkgrooves 102 and the stepped through holes and are uniformly arranged in 3 numbers along the circumferential direction of the housing 1.

Referring to fig. 10, a T-shaped groove is formed at the lower end of theupper block 4, an included angle between the T-shaped groove and the horizontal direction is 30-45 degrees, the axes of the circular holes d403 and e404 are perpendicular to each other, and the axes of the flow channels a401 and b402 are perpendicular to each other; the upper end of the lower block 2 is provided with a T-shaped groove, the included angle between the T-shaped groove and the horizontal direction is 30-45 degrees, and the middle part is provided with a rectangular through hole.

Referring to fig. 8, the upper portion of thepiston 7 is circumferentially provided with three joint surfaces having an included angle of 60 degrees, and each of the external joint surfaces is provided with a plurality of threaded holes.

Referring to fig. 3, the inclined plane at the upper end of thepush plate 8 forms an included angle of 30-45 degrees with the horizontal direction, 2-3 blind holes are arranged on the side surface, and a plurality of counter bores 802 are arranged at the lower end.

Referring to fig. 1 and 9, the lower boss of themandrel 11 is in a regular hexagonal shape, and a plurality of hydraulic throughholes 1101 in the radial direction are arranged on the hexagonal surface.

Referring to fig. 4, the joints of the throttle nipple B6, theupper stop 4 and the housing 1 are respectively provided with sealing rings 19 and 20; the shear pin 17 is connected with the joint of thepush plate 8 and the shell 1.

Referring to fig. 6, the lower stopper is coupled to the housing 1 through apositioning block 13.

Referring to fig. 1, the upper end of the lower joint 10 is provided with a thread, the center is provided with a stepped through hole along the axial direction, and the upper end of the lower joint 10 is connected with the lower end of the shell 1 through the thread; the lower end of themandrel 11 is connected with the lower joint 10 through threads, and the upper end of the mandrel passes through the inner hole of thepiston 7 and extends into the stepped hole of the shell 1.

Example 2 is most prominent compared with example 1 in that the drilling fluid impact force is increased at the sliding joint of the centralizing wing and the upper stop block, so that the centralizing wing can more easily protrude to act on the casing wall.

Exemplary embodiment 3

Fig. 1 and 2 show a casing section milling righting tool, wherein, the upper and lower ends of the casing 1 are provided with screw threads, and a stepped through hole is axially arranged, the stepped through hole is communicated with the upper and lower ends of the casing 1, and a rectangular sink 102 is arranged in the wall of the casing 1; the upper stop block 4, the righting wing 3 and the lower stop block 2 are sequentially arranged in the rectangular sinking groove 102; the piston 7 is arranged in a chamber A104 at the lower end of the shell 1 and forms sliding fit with the inner wall of the shell 1; the center of the piston 7 is provided with a step-shaped through hole, and the lower part of the piston is a cylinder; the upper end of the lower joint 10 is provided with threads, and the center of the lower joint is provided with a step-shaped through hole along the axial direction; the upper end of the lower joint 10 is connected with the lower end of the shell 1 through threads, and is provided with a sealing ring 25; the mandrel 11 is of a hollow structure, the lower end of the mandrel is provided with threads, the lower end of the mandrel is connected with the lower joint 10 through the threads, a sealing ring 24 is arranged, and the upper end of the mandrel penetrates through an inner hole of the piston 7 and extends into a stepped hole of the shell 1; a sealing ring 21 is arranged between the mandrel 11 and the piston 7, and a sealing ring 26 is arranged between the mandrel 11 and the stepped hole of the shell 1; the spring 16 is sleeved outside the mandrel 11; the nozzle 12 is disposed at the lower end of the mandrel 11 with a seal ring 23 disposed therebetween.

A rectangular hole 103 in the wall of the housing 1 shown in fig. 3 axially communicates therectangular sink 102 and the stepped through hole; the upper end of thepush plate 8 extends into the rectangular hole 103 of the shell 1 and is connected with the shell 1 through the shear pin 17; the upper end of thepush plate 8 is provided with an inclined plane, the included angle between the inclined plane and the horizontal direction is 30-45 degrees, and the side surface is provided with 2-3 blind holes; the throttle nozzle A5 is arranged in the round hole d403 of theupper stop block 4;

the shell 1 shown in fig. 4 is uniformly provided with 3 radial eccentric throughholes 101 along the circumferential direction; the throttle nozzle B6 is arranged in a radial eccentric throughhole 101 of the shell 1, one end of the throttle nozzle is provided with threads, the other end of the throttle nozzle is provided with a central hole with a certain depth along the axial direction, and a radial through hole is arranged at the middle necking part; one end of the throttle nozzle B6 is connected with the shell 1 through threads, and the other end of the throttle nozzle B6 penetrates through the round hole e404 of theupper stop block 4; aseal ring 19 is provided between the choke B6 and theupper stopper 4, and aseal ring 20 is provided between the housing 1 and the choke B6.

Therectangular sinking grooves 102 of the housing 1 shown in fig. 5 are offset from the axis of the housing 1 as a whole and are uniformly arranged in 3 along the circumferential direction of the housing 1.

The lower stopper 2 shown in fig. 6 is connected to the housing 1 through apositioning block 13, and thepositioning block 13 is connected to the housing 1 through ascrew 14.

As shown in fig. 7, 3 rectangular holes 103 are uniformly formed along the circumferential direction of thehousing 1, and 3push plates 8 respectively penetrate through the 3 rectangular holes 103.

The upper part of thepiston 7 shown in fig. 8 is circumferentially provided with three planes with an included angle of 60 degrees, and each plane is provided with a plurality of threaded holes; the thickness of thepush plate 8 is smaller than the width of the rectangular hole 103 of the shell 1, 2-3 blind holes are arranged on the side surface of thepush plate 8, a plurality of counter bores 802 are arranged at the lower end of thepush plate 8, and the lower end of the push plate is connected with thepiston 7 throughscrews 9.

Themandrel 11 shown in figure 9 is provided with a hexagonal shaped protrusion having 3 throughholes 1101 in the radial direction.

The upper end of the lower block 2 shown in fig. 10 and fig. 2 is provided with a T-shaped groove, the included angle between the T-shaped groove and the horizontal direction is 30-45 degrees, and the middle part is provided with a rectangular through hole.

Theupper block 4 shown in fig. 11 to 13 is provided with circular holes d, e403 and 404 and circular cross-section flow channels a, b401 and 402, the lower end of the upper block is provided with a T-shaped groove, the included angle between the T-shaped groove and the horizontal direction is 30-45 degrees, the axes of the circular holes d403 and e404 are mutually vertical, and the axes of the circular cross-section flow channels a401 and b402 are mutually vertical.

Fig. 14 is a schematic structural diagram of a structure in which a straighteningwing 3 of a casing segment milling centering tool extends, the straighteningwing 3 extends along a T-shaped groove of anupper stop block 4 and a lower stop block 2, and the upper end surface of the straighteningwing 3 is in contact with the lower end surface of a choke B6.

As shown in fig. 15, after theinner casing 54 and thecement sheath 53 between the two casings are milled, thenext milling device 55 mills theouter casing 52. A casing section millingcentralizer tool 56 is used in the section milling of theouter casing 52, the tool being connected in series below asection mill 55, thesection mill 55 and the centralizer tool being fed into a predetermined position by thedrill pipe 51. A pump is started at the wellhead, the drilling fluid passes through the interior of the drill rod and reaches the centralizing tool, and a part of the drilling fluid is discharged into a shaft through thenozzle 12; the other part of the drilling fluid passes through a stepped through hole and a throttling nozzle B6 in the shell 1, then enters a circular section flow channel a401 of theupper stop block 4 through a throttling nozzle A5, and then is discharged into arectangular sinking groove 102 of the shell 1; a further portion of the drilling fluid enters chamber B27 throughbore 1101, causing the pressure at the lower end ofpiston 7 to be greater than the pressure at the upper end; when the displacement reaches a set value, thepiston 7 moves upwards along themandrel 11 under the action of hydraulic pressure, thepush plate 8 pushes the centeringwing 3 to extend outwards along the T-shaped grooves of theupper stop block 4 and the lower stop block 2 until the upper end surface of the centeringwing 3 is in contact with the lower end surface of the choke B6, the centeringwing 3 extends completely, so that thesegment milling device 55 is centered, and thespring 16 is in a compressed state at the moment. Theouter casing 52 can be milled in sections; after the section milling operation is finished, the discharge capacity of a ground slurry pump is reduced, and when the discharge capacity is smaller than the set discharge capacity, thepiston 7 is reset under the action of the restoring force of thespring 16; in the process of lifting the pipe string to recover the tool, when the rightingwing 3 of the righting tool meets theinner casing 54, the rightingwing 3 is pushed back into therectangular sink 102 of the housing 1, and can be recovered to the ground through theinner casing 54.

Claims (10)

1. A centralizing tool for milling a casing section comprises a shell (1), an upper stop block (4), a centralizing wing (3), a lower stop block (2), a spring (16), a piston (7), a mandrel (11) and a lower joint (10); the method is characterized in that: also comprises a push plate (8) and a nozzle (12);

the upper end and the lower end of the shell (1) are provided with threads, the lower end of the shell is hermetically connected with the lower joint (10) to form a hollow cylindrical structure, the lower section of the shell (1) is provided with a piston cavity (104) with expanded diameter, the upper section of the shell is circumferentially and eccentrically provided with 3-5 rectangular sinking grooves (102), and the middle section of the shell is provided with a rectangular hole (103) axially corresponding to the upper rectangular sinking groove (102);

the mandrel (11) is arranged in an expanding piston cavity at the lower section of the shell (1), the upper end of the mandrel is hermetically connected with the middle section of the shell (1), the lower end of the mandrel is hermetically connected with a lower connector through a reducing nozzle (12), a stepped through hole structure is axially arranged in the mandrel, a lower boss is arranged on the periphery of the mandrel, the lower part of the lower boss is in blocking fit with the lower connector (10), and a plurality of hydraulic through holes (1101) are radially distributed;

the piston (7) is sleeved above the lower boss of the mandrel (11), the inner wall of the piston is in axial sliding sealing fit with the mandrel (11), the outer wall of the piston is in axial sliding sealing fit with a piston cavity (104) of the shell (1), and connecting surfaces which are in one-to-one correspondence with the rectangular holes (103) are arranged on the upper portion of the piston (7) in the circumferential direction;

the spring (16) is sleeved on the mandrel (11) above the piston (7);

the upper stop block (4), the righting wing (3) and the lower stop block (2) are sequentially arranged in the rectangular sinking groove (102), and the righting wing (3), the upper stop block (4) and the lower stop block (2) form sliding limit fit according to the same inclination angle;

the push plate (8) penetrates through the rectangular hole (103) in the middle section of the shell (1) in a sliding mode, the outer inclined plane of the upper end of the push plate is in sliding limit fit with the inner inclined plane of the righting wing (3), and the lower end of the push plate is fixed with the connecting surface of the piston (7).

2. The casing section milling centralizer of claim 1, wherein: the upper end of the shell (1) is radially provided with an eccentric through hole (101), an upper stop block (4) is provided with a horizontal round hole d (403), a round hole e (404), a vertical flow channel a (401) and a horizontal flow channel B (402), the eccentric through hole (101) is crossed with the round hole e (404) of the upper stop block (4), a throttling nozzle A (5) is arranged in the round hole d (403), a throttling nozzle B (6) is arranged in the eccentric through hole (101), one end of the throttling nozzle B (6) is connected with the shell (1), the other end of the throttling nozzle B passes through the round hole e (404) of the upper stop block (4) and is communicated with a flow guide hole radially arranged on the shell (1), the throttling nozzle B (6) is communicated with the throttling nozzle A (5) through the flow channel B (402), and the throttling nozzle A (5) is communicated with the rectangular sinking groove (102) through the flow channel a (401).

3. The casing section milling centralizer of claim 2, wherein: the upper end of the push plate (8) is connected with the joint part of the shell (1) through a shear pin (17); the radial eccentric through holes (101) of the shell (1) are uniformly provided with 3 along the circumferential direction of the shell (1), the rectangular sunk grooves (102) are wholly deviated from the axis of the shell (1) and are uniformly provided with 3 along the circumferential direction of the shell (1), and the rectangular holes (103) are communicated with the rectangular sunk grooves (102) and the stepped through holes along the axial direction and are uniformly provided with 3 along the circumferential direction of the shell (1).

4. The casing section milling centralizer of claim 3, wherein: the lower end of the upper stop block (4) is provided with a T-shaped groove, an included angle between the T-shaped groove and the horizontal direction is 30-45 degrees, the axes of the round hole d (403) and the round hole e (404) are mutually vertical, and the axes of the flow channel a (401) and the flow channel b (402) are mutually vertical; the upper end of the lower stop block (2) is provided with a T-shaped groove, the included angle between the T-shaped groove and the horizontal direction is 30-45 degrees, and the middle part is provided with a rectangular through hole.

5. The casing section milling centralizer of claim 4, wherein: the upper part of the piston (7) is circumferentially provided with three connecting surfaces with an included angle of 60 degrees, and each external connecting surface is provided with a plurality of threaded holes.

6. The casing section milling centralizer of claim 5, wherein: the inclined plane of the upper end of the push plate (8) forms an included angle of 30-45 degrees with the horizontal direction, 2-3 blind holes are arranged on the side surface, and a plurality of counter bores (802) are arranged at the lower end.

7. The casing section milling centralizer of claim 6, wherein: the lower boss of the mandrel (11) is in a regular hexagonal shape, and a plurality of hydraulic through holes (1101) in the radial direction are arranged on the hexagonal surface.

8. The casing section milling centralizer of claim 3, wherein: the joint of the throttle nozzle B (6), the upper stop block (4) and the shell (1) is respectively provided with a sealing ring (19, 20); the shear pin (17) is connected with the joint of the push plate (8) and the shell (1).

9. A casing section milling centralising tool as claimed in claim 1 or 2, wherein: the lower stop block (2) is connected with the shell (1) through a positioning block (13).

10. A casing section milling centralising tool as claimed in claim 1 or 2, wherein: the upper end of the lower joint (10) is provided with threads, the center of the lower joint is provided with a step-shaped through hole along the axial direction, and the upper end of the lower joint (10) is connected with the lower end of the shell (1) through the threads; the lower end of the mandrel (11) is connected with the lower connector (10) through threads, the upper end of the mandrel penetrates through an inner hole of the piston (7) and extends into a stepped hole of the shell (1), and the lower end of the push plate (8) is connected with the piston (7) through a bolt (9).

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